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Discussion about pinch

Discussion about pinch. Particle pinch Heat pinch Linkage between particle and heat pinch. . Remained i ssues of particle pinch. Present gyrokinetic study is limited at particular location ( r ~0.5). How about other location? Are there no man’s land *in particle transport?

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Discussion about pinch

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  1. Discussion about pinch Particle pinch Heat pinch Linkage between particle and heat pinch.

  2. Remained issues of particle pinch Present gyrokinetic study is limited at particular location (r~0.5). How about other location? Are there no man’s land *in particle transport? Present gyrokinetic analysis is linear and quasi linear analysis. Does any non linear effects (zonal flow , mode coupling) change results significantly?→Some publication says there are no significant modification (Angioni NF2010 etc). Particle transport analysis in L-H transition and ITB formation will be important. Linkages with other pinch (heat pinch and momentum pinch or residual stress) will be important as well. RMP effects on particle transport is now hot topic. * No man’s land is area where gyrokinetic simulation cannot account for experimental observation. DIII-D results shows r>0.6 is no man’s land.

  3. Remained issues of heat pinch Are there any heat pinch observation in non ECRH plasma? Does any simulation work explain heat pinch observation? Does heat pinch help plasma operation or confinement improvement?

  4. In power balance analysis, heat pinch doe not appear explicitly. It is not clear from temperature profile Linear without pinch Linear with pinch Non linear without pinch Non linear with pinch cPB cPB cPB cinc cPB cinc cinc cinc Non Linear Linear or With Pinch Without Pinch or

  5. In DIII-D, off axis ECH heating caused increase of central Te (Luce et al., 1992) Outward Inward Inward heat pinch is necessary to explain the observation. Mechanism was not understood in “1992”. What now?

  6. Te gradient -heat flux relation was measured to investigate heat pinch and nonlinearity in LHD and JT-60U from cold pulse propagation. Inagaki et al., NF2006 LHD ctr Vtr With use of non linear model of cewithout pinch, heat pinch appears in transient analysis

  7. LHD results shows small non linearity (b=0→ctr~cPB) and finite transient pinch (a≠0). In JT-60U, a≠0, b≠0 Agreements between cpb and ctr. LHD Rax=3.6m Small non linearity is similar character to particle transport. Ne profile shows flat gradient in core (r<0.6) suggesting no pinch in equilibrium state (transient particle pinch is not clear). Further investigation is necessary.

  8. Linkage between pinch (linkage with off diagnoal term) Are there any clear observation linkage between pinches→Are there any clear coupling of transports (heat, particle , momentum) 2. How should we care about linkage between pinches? Highest density peaking is achieved at ITG/TEM transition. What happen to heat pinch or momentum pinch at ITG/TEM transition?→Are transition between Co and Ctr intrinsic flow?

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